Cardiac involvement in infantile Sandhoff disease.

An 18-month-old boy with enzyme assay-confirmed infantile Sandhoff disease (MIM 268800) is reported. Besides the classical neurological features, this patient exhibited severe mitral regurgitation secondary to mitral valve prolapse and mild aortic regurgitation from aortic valve prolapse. He also had asymmetric hypertrophy of the interventricular septum without left ventricular outflow tract obstruction.